Tuesday, May 10, 2011

Announcements:

• A concept survey (pre-test) will be administered tomorrow in Phillips 265.  This multiple-choice survey requires no special preparation; it is simply a way to assess your current understanding of key physics concepts.  Be sure to attend one of the three half-hour sessions, and bring your laptop computer with you so that you can enter your answers electronically.  See page 13 in your lab manual for more information about this concept survey.
• 9:45 - 10:15 (right after this class)
• 11:30 - 12:00
• 1:00 - 1:30
• Labs start on Thursday  - see lab schedules posted in hall and online.
• Lab manuals are available in the campus bookstore or for free via WebAssign.
• Laptop computers are not needed in class, but will be needed in lab.
• Keep your own class notes separate from what you will turn in today.

Assignments:

•  Introduction to Mastering Physics is due tonight at midnight (this assignment is for practice and should take ~30 minutes).
•  Read Chapter 1 in your textbook and submit HW1 by midnight tomorrow 
• Note:  Answers to most of the suggested homework problems are in the back of your book.
•  Review solution for sample real-world problem: Pizza Problem.

Student information survey - Complete and return this survey for class participation credit.

Syllabus review and overview of course

Instructional philosophy

Introduction to Mastering Physics
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Note: Class e-mail will be sent to the email address provided through the university directory listing.  Note that you can forward email from your UNC account via the ONYEN website.

Student poll: Which edition of the Walker textbook do you prefer: 3^rd or 4^th edition?

Chapter 1: Introduction to Physics

All of physics is based on empirical (experienced or experimental) evidence, which requires measurements to be made. These measurements must be standardized and sufficiently precise in order to make comparisons with other scientists so that a meaningful discussion can be made as to whether a theory is or is not supported by experimental findings.

SI Unit notation and dimensions:
[length] = m     1 m ~ 3.3 ft
 [mass] = kg    1 kg ~ 2.2 lbs.
 [time] = s  

Becoming familiar with mks units:

• Distance from floor to waist of your instructor:  ~ 1 m
• Length of forearm (fingers to elbow): 1 cubit, ~ 0.5 m, 18 in
• Width of your smallest fingernail:  ~ 1 cm
• Thickness of a single page from your physics textbook:  ~0.1 mm
• Mass of your physics textbook (in kg), weight in pounds (lb):  ~2 kg, ~5 lbs.
• Mass of a nickel coin (in grams):  5.00 g
• Your heart rate (in Hz): ~1 Hz
• Slow walking speed: ~ 1 m/s ~ 2 mph
• Highway speed: ~ 60 mph ~ 30 m/s
• Number of seconds in a year:  ~ pi*10^7  (by coincidence?)

Trigonometry mneumonic:  SOH-CAH-TOA
   Sine is Opposite side over Hypoteneuse
   Cosine is Adjacent over Hypoteneuse
   Tangent is Opposite over Adjacent

Exercise:  What are the angles inside a 3-4-5 triangle?

Significant figures and estimations:

Why is it wrong to show extra digits when reporting numbers?

Why is it best to keep at least one extra digit and avoid rounding until the end of a calculation?

Critique this statement: 1 + 1 = 3 for large values of 1.

Fermi problem:  Estimate the number of molecules in a drop of water.

RWP1 – pizza problem

A physics lesson from the art of juggling.

Introduction of Supplemental Instruction leader: Dmitry Spivak

Student poll: What are preferred times for SI sessions? Dmitry is available 5-7 pm, and potentially other times.